1. Technical Field
The present invention relates to a small-sized pump that moves a liquid by changing a volume inside a pump chamber through a piston or a diaphragm and the like.
2. Related Art
There has been proposed a high output pump having a piston or a diaphragm driven by a piezoelectric element such as a PZT, a pump chamber capable of changing the volume by the diaphragm or the piston, an inlet passage to permit an operating fluid to flow into the pump chamber; an outlet passage to permit the operating fluid to flow out of the pump chamber; and a fluid resistance element such as a check valve provided on the inlet passage and the outlet passage. In this pump, an inertance value of the inlet passage is smaller than the inertance value of the outlet passage and the amount of outlet fluid is large corresponding to a high load pressure (Refer to Japanese Unexamined Patent Application Publication No. 2002-62986).
In the pump disclosed in Publication No. 2002-62986, the output is increased by the inertia effect of a fluid having a large inertance at the outlet passage. There is a problem in that the change of the inertia effect caused by the change of a driving waveform of a piston or a diaphragm or a pump size affects the output seriously.
Therefore, the present invention is intended to provide a method of driving a high output pump by using the inertia effect.